Question 21 on applications for troops seeking national-security jobs asks if the applicant has ever needed any mental-health counseling. Troops with post-traumatic stress disorder or martial problems are exempted. Victims of military sexual assault are not.

The top US commander in Afghanistan says the shooting spree in which Robert Bales has been charged, as well as a recent Quran burning and a video of Marines urinating on dead Taliban are all examples of a failure of good oversight from commanders.

Reports of suicide bomb vests inside the Afghan Department of Defense were eventually dismissed as false, but they pointed to US concerns about Taliban infiltrators or rogue troops attacking US soldiers or the Afghan government.

Twenty percent of active-duty Army troops are on at least their third tour of duty to a war zone. Sgt. Robert Bales, suspected of slaying 17 Afghan civilians, was one. Here's what's known about the dangers of repeated deployments.

In the killing of 16 Afghan villagers, Staff Sgt. Robert Bales' defense team may build their case on post traumatic stress disorder. Though PTSD can be connected to aberrant and violent behavior, it's a hard case to make in court.

Staff Sgt. Robert Bales joined the Army shortly after the 911 terrorist attacks, and he served three tours in Iraq before being sent to Afghanistan. Now he sits in the military prison at Fort Leavenworth, Kansas, charged with killing 16 Afghan villagers.

Defense Secretary Leon Panetta is in Afghanistan to try to repair relations after the Quran-burning incident and a mass shooting of civilians. The fact that the US has spirited away the accused shooter complicates his mission.

The Army sergeant alleged to have killed 16 Afghanistan civilians on Sunday acted alone, Pentagon officials continue to say. They are treating it as an isolated incident, not as a sign of mounting frustration within US ranks about the Afghanistan war.